Scratcher for wells



S. A. KIPPER SCRATCHER FOR WELLS NIH" H April 6, 1954 3 Sheets-Sheet 1 Filed Nov. 17, 1949 my ll 505100279. Mp Ee,

1 N V EN TOR.

AWTOPK/EVS' April 6, 1954 s. A. KIPPER SCRATCHER FOR WELLS 3 Sheets-Shet 2 Filed Nov. 17, 1949 m 8 7 $1M $23, a l 2 b 5 m 2 I. 1:; II \PDJM KW m -i i a v.

INVENTOR.

Saw/727 7; MppE/Q April 6, 1954 s. A. KIPPER SCRATCHER FOR WELLS 5 Sheets-Sheet 3 Filed Nov. 17, 1949 INVENTOR. ijl fl HTTOENE'VS Patented Apr. 6, 1954 SCRATCHER FOR WELLS Stewart A. Kipper, Glendale, Caliii, assignor, by mesne assignments, to Kenneth A. Wright,

Long Beach, Calif.

Application November 1'1, 1949, Serial No. 127,954

3 Claims. 1

This invention relates to apparatus used in drilling and completing wells and is particularly directed to improvements in devices for removing the mud cake or sheet within the well bore prior to and during cementing operations. This invention constitutes an improvement over the apparatus shown in the copending application of Kenneth A. Wright, filed September 25, 1 4 entitled Wall scratcher for Wells and bearing Serial No. 51,237, new Patent No. 2,506,405.

The principal object of the present invention is to provide a novel form of wall scratcher for wells which is universal in application in that it may be carried on a collar which is fixed to a well pipe or mounted for rotary or longitudinal movement, or both, thereon, or may be carried on a longitudinally extending strip which is fixed to the pipe.

Another object is to provide a novel form of wall scratcher of this type which includes a mounting for outwardly extending spring fingers, the mounting being of minimum radial thickness.

Another object is to provide a wall scratcher for removing mud cake from a well bore which employs a plurality of spring fingers mounted in pairs on the outer surface of a carrier strip and secured in position thereon by individual cover elements.

Another object is to provide a scratcher of this type in which each of the pairs of spring fingers is formed integrally from a single length of wire whereby a sturdy mounting is provided which employs a minimum number of parts.

Another object is to provide a scratcher of this type wherein the spring fingers of each integral pair extend from one end of an individual-coil spring, the coil springs of each pair being spaced but having a common axis.

A related object is to provide a scratcher having coil springs of this type wherein the coils are wound in opposite directions so that the spring fingers extending from each are positioned symmetrically at opposite ends of the springs and on the opposite side of the spring from the carrier strip which supports the pairs of spring fingers.

Another object is to provide an improved form of wall scratcher having spring fingers mounted in pairs and each extending from coaxial coil springs, each pair of spring fingers being secured to the outer surface of a carrier strip by means of individual ported cover plates which enclose the springs and wherein clearance openings are provided in the carrier strip for reception of the spring coils.

Other objects and advantages will appear more fully hereinafter.

In the drawings:

Figure l is a side elevation partly broken away showing a pref-erred embodiment of my invention as positioned on a well pipe.

Figure 2 is a sectional plan view taken substantially on the lines 22 as shown in Figure 1.

Figure 3 is a fragmentary side elevation on an enlarged scale showing details of mounting of the individual spring finger units.

Figure 4 is a sectional elevation taken substantially on the lines 4-4 as shown in Figure 3.

Figure 5 is an exploded view partly in section showing the manner of assembly of spring finger units, carrier strip and cover member.

Figure 6 is a view similar to Figure 1 showing spring fingers having a modified form of tips.

, Figure '7 shows a modified form of carrier strip which may be applied laterally to the pipe and which encompasses less than a full circle.

Figure 8 is a sectional plan view taken substantially on the lines 8-8 as shown in Figure 7.

Figure 9 is a View similar to Figure 8 showing spring fingers having upturned tips.

Figure 10 shows the spring finger units mounted on a helical carrier strip which may be fixed to the well pipe.

Figure 11 is a sectional plan view taken substantially on the line ll-ll as shown in Figure 10.

Figure 12 is a view similar to Figure 10 showing spring finger units having upturned tips.

Figures 13 and 14 show the spring finger units mounted on a carrier strip extending longitudinally of the pipe, the fingers in Figure 13 being provided with upturned tips.

Figures 15 to 19 show idealized sectional plan views illustrating spring fingers which extend at various angles from their mounting location on a well pipe or on a collar encircling the well pipe. Only one spring finger is shown in each view, the others being omitted for clarity of illustration. Figure 15 is a plan view taken on lines iii-i5 as shown in Figure 14 and showing a spring finger extending at a preferred angle from its mounting; Figure 16 shows a spring finger extending radially; Figure 19 shows a spring finger extending tangentially; and Figures 17 and 18 show spring fingers extending at angles intermediate the radial position of Figure 16 and the tangential position of Figure 19.

Referring to the drawings, a well pipe l0 extends into a well bore ll. At spaced intervals along the well pipe a plurality of well scratcher assemblies I2 may be mounted. Each of these scratcher assemblies includes a mounting element or carrier strip l3 and a plurality of scratcher units hi positioned thereon for contacting the wall of the bore hole The carrier strip may take various forms. As shown in Figure 1 the carrier strip |3 comprises a segmental link or collar loosely mounted on the well pipe it for relative rotary movement and for relative longitudinal movement between stop lugs l5 and l5 which maybe provided on the pipe. The carrier strip L? is preferably formed of two matching collar halves connected by pins H in order that the device I2 may be readily mounted on a well pipe and applied laterally thereto. A preferred form of hinge for connecting the collar halves is shown in the copending application of Kenneth A. Wright, for Centralizer for Well Pipe, filed April 10, 1948, bearing Serial No. 20,318.

The carrier strip may also take the form of collars l8 which partially encircle the pipe It as shown in Figures '7, 8 and 9, or may take the form of helical strips It as shown in Figures 10 and 12. The collars l8 and helical strips 19 are preferably fixed to the pipe by welding. The carrier strip may also take the form of longitudinally extending mounting plates 23 as shown in Figures l3 and 14. These strips are fixed to the pipe in by any convenient means such as by welding, and it is preferred to employ a plurality of such strips positioned at various angular locations about the pipe l0.

Each of the scratcher units M which is mounted on one of the several forms of carrier strips comprises a pair of spring fingers which are parallel in their free, unconfined position. These parallel fingers are formed integrally from the same continuous length of spring wire. The wire is formed to provide a pair of coaxial coils 23 and 24 and a joining connection 25. This connection 25 is V-shaped oiiset with respect to the axis of the coils 23 and 24 as clearly shown in Figure 5 and is adapted to lie against the outer surface 28 of the carrier strip 93. The coils 23 and 24 are formed as helices with opposite leads. Thus, as shown in Figure 5 the coil 23 has a left-hand lead and the coil 24 has a right-hand lead. By means of this provision each of the spring fingers 2i and 22 extends from the outer end of its respective coil and from the side thereof opposite the position of the carrier strip I3.

Clearance openings 22 and 28 are punched or otherwise formed in the carrier strip 28 to receive a portion of each of the coils 23 and 23. As shown clearly in Figure 4 the coils 23 and 24 extend into the clearance apertures 21 and 28 respectively for a distance approximately equal to the thickness of the carrier strip iii. In this way the coils 23 and 24 are substantially flush with the inner surface 29 of the carrier strip 13.

The offset joining connection 25 lies flush against the outer surface 25 of the carrier strip l3 and is maintained in that position by means of the attaching clip or ported cover 30. The cover 38 is secured to the carrier strip is by any convenient means such as, for example, spot welding 3|. The cover 36 may conveniently be formed from fiat sheet by stamping operations to provide a housing 38 which merges with a base flange 32. A laterally extending channel 33 is also formed by the stamping operation, and this channel merges at both ends with the housing 3|. The channel 33 is shaped to confine the offset joining connection 25 tightly against the outer surface 26 of the carrier |3 and the coils 23 and 2d are enclosed within the housing 3|. Apertures 34 are provided in the opposite ends of the housing 3| so that the spring fingers 2| and 22 may extend outwardly therethrough and have clearance with respect to the cover 30. When the base flange 32 is spot welded to the carrier strip l3 the cover is anchored solidly in place and the pair of fingers 2| and 22 are provided with a reliable mounting on the carrier strip l3. It will be understood that it is not practicable to weld the joining connection 25 or any portion of the continuous wire directly to the carrier strip because the spring wire is not easily weldable.

Since the fingers 2| and 22 extend from the ends of coils the fingers in effect are provided with a spring base so that they may deflect readily in any direction. Furthermore, the normal free pos tion of the outwardly extending spring fingers may be set at any desired angle since the axis of the coils extends longitudinally of the well pipe and not radially thereof. The spring fingers 2| and 22 therefore may extend at any desired angle as illustrated by Figures 15 to 19 inclusive.

The extending ends of the spring fingers 2| and 22 may be plain as shown in Figures 6, '7, 8, 10, 11 and 14, or may be provided with an upturned tip 35 as shown in Figures 1, 2, 9, 12 and 13.

The carrier strips I30; as shown in Figures 7, 8 and 9 extend for slightly more than one-half a full circle so that they may be sprung sufficiently to be installed laterally on the well pipe H). The strips are then secured in place by any convenient means such as, for example, by welding. The helical strips 53b shown in Figures 10 and 12 may be applied in the same manner, and as shown in Figure 11 these helical strips also extend for slightly more than one-half way around the pipe in. The carrier strips shown in Figures l3 and are secured directly to the pipe If] by welding.

It will be observed that the scratcher unit generally designated M is substantially the same for each of the various types of carrier strips. Accordingly, manufacturing economies ar made possible because the same covers 36 and spring wire pairs may be employed for constructing scratcher units having any desired form of carrier strip. Furthermore, the resulting mounting for the spring fingers in each case occupies only a minimum of thickness in a direction radial to the well pipe.

Having fully described my invention, it is to be understood that I do not wish to be limited to the details herein set forth, but my invention is of the full scope of the appended claims.

I claim:

1. In a wall scratcher assembly for wells, the combination of a carrier strip adapted to be mounted on a pipe insertable into a well bore, a plurality of scratcher units mounted on the carrier strip, each of the scratcher units including a pair of spaced fingers extending outwardly from the carrier strip, each pair of fingers being formed from a continuous length of wire terminating at the outer ends of the fingers, said length of wire being formed with spaced coils of opposite lead from which the fingers extend symmetrically and an intermediate portion between the coils, the carrier strip having clearance apertures formed therein, the coils extending longitudinally of the pipe and each having a plurality of convolutions projecting through the apertures and substantially flush with the inner surface of the carrier strip, and each scratcher unit including a cover element for securing said intermediate portion of the length of wire against the outer surface of the carrier strip, the cover element being provided with ports through which the fingers extend.

2. In a wall scratcher assembly for wells, the combination of an annular collar adapted to be mounted on a pip insertable into a Well bore, a plurality of scratcher units mounted on the outer surface of the collar, each of the scratcher units including a pair of spaced fingers extending outwardly from the collar, each pair of fingers being formed from a continuous length of wire terminating at the outer ends of the fingers, said length of wire being formed with spaced coaxial coils of opposite lead from which the fingers extend symmetrically and a Vshaped intermediate portion between said coils, said fingers extending from the outer end of each of said coils and from the sides thereof remote from the annular collar, the collar having clearance apertures formed therein for reception of a portion of each of the coils, and each scratcher unit including a cover element having a I-shQped groove for receiving and securing said V-shaped intermediate portion of the length of wire against the outer surface of the collar.

3. In a wall scratcher assembly for Wells, the combination of: an annular collar adapted to be mounted on a pipe insertable into a well bore, a plurality of scratcher units mounted on the outer surface of the collar, each of the scratcher units including a pair of spaced fingers extending outwardly from the collar, each pair of fingers being formed from a continuous length of wire terminating at the outer ends of the fingers, said length of wire being formed with spaced coils of opposite lead from which the fingers extend symmetrically and a connecting section between said coils, the said connecting section having an intermediate offset portion adapted to engage the outer surface of the collar, said fingers extending from the outer end of each of said coils and from the sides thereof remote from the annular collar, each scratcher unit including an attachment element having a groove for receiving and securing said intermediate offset portion of the length of wire against the outer surface of the collar.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,358,481 Traphagen Nov. 9, 1920 2,150,435 Floreth Mar. 14, 1939 2,364,303 Martin Dec. 5, 1944 2,412,876 Edwards Dec. 17, 1946 2,421,434 Reistle, Jr., et al June 3, 1947 2,506,405 Wright May 2, 1950 

